The present invention relates to an improved radiator cooling fan having a planar mounting hub and blades extending radially therefrom.
A variety of fan structures have been developed for use in automotive cooling systems. These fan structures must be capable of withstanding extreme environmental conditions and minimizing operational noise levels while still providing suitable airflow over the radiator and vehicle engine. Therefor, it is important that radiator cooling fans be ruggedly constructed so as to provide long service life substantially free from maintenance.
In addition, it is important that radiator cooling fans weigh as little as possible, since increased weight may adversely affect the operational life of other associated engine components, such as the water pump. Accordingly, the construction of prior art cooling fans has required a compromise between durability and the overall weight of the fans.
Finally, due to the highly competitive nature of this industry and the large volume of radiator fan structures sold annually, small savings in the cost of manufacture can be of significant importance.
Typical prior art fan structures include a central, spider-like member having a single blade attached to each of the radiating arms thereof. The arms of the spider are twisted to provide an appropriate angular displacement for the blades. Significantly, the spider members of such prior art radiator cooling fans usually require a stress relieving process to assure that the spider arm twist operation does not introduce small cracks which would impair the structural integrity of the fan for the normal operating life of the vehicles in which they are used. In addition, due to the extreme and prolonged forces to which these fans are exposed, the spider members of prior art fans are typically constructed from heavy gauge metals.